Apparatus for manufacturing a molding continuously

ABSTRACT

A process and apparatus is provided for automatically and continuously producing a mass of moldings. A continuous molding is manufactured by injecting a solid solution in order of precedence into a plurality of molds circulating in a line along an endless track and by solidifying the injected solution. The solution is preferably vinyl chloride resin or another synthetic resin. After the solution solidifies the mold is automatically removed from the molding. The continuous molding consists of a number of moldings open at the bottoms and connected end to end by a top plate, molded at the same time.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a process and apparatus forcontinuously manufacturing a molding having a number of spaces closed atthe top and open at the bottom.

2. Description of the Related Art

Conventional processes and apparatus for manufacturing honeycombmoldings which are open at the top include general injection moldingprocesses and apparatus. The operation of processes and apparatus ofthis type is well known, simple, and follows a set procedure. Theseprocesses and apparatus make it possible to manufacture moldingsreliably.

In some circumstances, there may be a need to manufacture largequantities of moldings relatively inexpensively in a very short period.In other words, the quantity, the delivery deadline, or the costs maytake priority over the accuracy of the molding shape and size. In thiscase, it is difficult to manufacture moldings by the conventionalprocesses and apparatus, and it is, therefore, necessary to consider theuse of a mass production system for producing the moldings.

By way of example, a molding of the type which needs to be producedrelatively cheaply in a very short period of time is a lawn protector.Lawn protectors have been receiving attention for some time. Lawnprotectors are laid on a lawn parking lot. Cars can be parked on theprotectors so that their tires do not press on the lawn directly. Thisprotects the lawn and does not prevent it from growing. FIG. 2 of theaccompanying drawings shows part of a honeycomb molding A, which is alawn protector.

The need to manufacture a mass of such honeycomb moldings at high speedtakes priority over the need to improve the accuracy of their shape andsize. It is difficult to manufacture such moldings at high speed withthe conventional injection molding systems. In order for a process or anapparatus to manufacture honeycomb moldings at high speed, it isnecessary to introduce a continuous manufacturing system, which may bean extrusion molding system, in place of a conventional injectionsystem.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a process and an apparatusfor automatically and continuously producing a mass of moldings withoutthe disadvantages arising in the establishment of a mass productionsystem using the conventional apparatus of injection molding systems.This is accomplished through a continuous manufacturing system using asolid solution extrusion system having a circulation system with molds.

In accordance with an aspect of the invention, a process is provided formanufacturing a continuous molding by injecting a solid solution inorder of precedence into a plurality of molds circulating in a linealong an endless track, and by solidifying the injected solution. Thetrack includes a forward path and a backward path. The backward pathextends substantially horizontally or slopes down under the forwardpath. The front end of the forward path is positioned just under thefront end of the backward path. The rear end of the forward path ispositioned just under the rear end of the backward path. The continuousmolding consists of a number of moldings connected end to end by amolded top plate. The moldings are open at their bottoms. The processcomprises the steps of:

injecting the solution into each of the molds moving along the forwardpath;

removing the continuous molding from each of the molds by displacing themold down, little by little in order of precedence from the molding inclose contact with the mold while the injected solution is solidifying;

moving from the front end of the forward path down to the front end ofthe backward path, the mold released from the removing step;

returning the mold along the backward path; and

lifting the mold from the rear end of the backward path to the rear endof the forward path.

By injecting a solid solution from an extrusion type injector into themolds in order of precedence, this process can continuously manufacturea continuous molding consisting of a number of moldings open at thebottoms and connected end to end by a top plate, molded at the sametime. As a result, it is possible to realize a mass production system,which can greatly lower the molding production costs.

In accordance with another aspect of the invention, an apparatus isprovided for manufacturing a continuous molding continuously byinjecting a solid solution in order of precedence into a plurality ofmolds circulating in a line along an endless track, and by solidifyingthe injected solution. Each of the molds includes a plurality of pinswhich can protrude up into cavities in the mold. The continuous moldingconsists of a number of moldings connected end to end by a molded topplate. The moldings are open at the bottoms. The apparatus includes:

conveying means for horizontally conveying the molds in close contactand in series along the track;

injecting means for injecting the solution into each of the molds movingforward along the track, the injecting means being positioned above thestarting point where the conveying means starts conveying the molds;

a pressurizer for pressing the upper surface of the injected solutionwith a predetermined pressure to make the surface continuously flat, thepressurizer being positioned adjacently to and downstream from theinjecting means;

guide means for guiding the molds gradually down by using the conveyingforce;

removing means for protruding the pins up as the molds are moving down;and

circulating means for circulating to the starting point the moldsremoved from the molding.

This apparatus can implement the foregoing process securely. Theapparatus includes molds of the same shape. By circulating the molds,the apparatus can make a molding continuously. This makes the moldingproduction costs relatively low. While the guide means is moving each ofthe molds gradually down, the pins protrude up into the cavities in themold to remove the molding already cooled and solidified in the mold.This makes the removal secure.

It is preferable that each of the molds include guide rollers which canbe guided by the guide means in such a manner that, while the mold ismoving forward along the guide means and gradually down out of closecontact with the molding, the mold is kept horizontal. This enables thelocus of the mold moving during the removing step to be limited to thehorizontal (direction) by the synthesis of the substantially horizontalmovement and vertical movement of the mold. The position of the moldcan, therefore, be kept always horizontal, although it tends to tilt.

If a mold tilted when the injected solution in it has not completelysolidified, the upper surface of the solution might start solidifyingwhile it is not horizontal. This makes the molding bad in shape. If aninclined mold were removed down from the molding, the mold surfacessliding on the adjacent molds would not be vertical. This prevents theremoval from being smooth. It is very easy to solve these problems bykeeping the molds individually horizontal while the molds are removedfrom the molding.

It is preferable that the apparatus further include means for urgingforward and backward into close contact at least two of the molds movingduring a period of a molding step in which the molds move forward whilethe solution is injected into the molds.

When the solution is injected into each of the molds during the periodof the molding step, the injection pressure might otherwise separateadjacent molds. This defines gaps between the molds, through which thesolution may leak out. By limiting the period during which the solutionis injected, and by urging the molds forward and backward into closecontact, it is possible to keep the solution from leaking out throughthe gaps. It is therefore possible to inject the solution safely andsecurely.

It is preferable that the apparatus further include means for urgingforward the rear end of the mold having circulated and returned to thestarting point, and for urging backward the front end of the mold at theend of the forward mold movement. This urging means brings all the moldsin the molding step into close contact. This makes it possible to keepthe apparatus operating without preventing the molds from moving downsmoothly from the molding, and from returning smoothly to the startingpoint of the production.

Each of the molds may include a formwork, an intermediate plate and amovable plate. The formwork has the cavities corresponding to themolding. The intermediate plate closes the lower side of the formworkand has pin holes. Each of the pins extends through one of the holes insuch a manner that the pins can protrude from the holes into thecavities. The pins are embedded in the movable plate in such a mannerthat they extend toward the intermediate plate. The movable plate canmove toward and away from the intermediate plate within a predeterminedrange. Otherwise, the formwork and the intermediate plate might beintegral. In this case, the molds are simple in structure. The movableplate can move toward and away from the intermediate plate within thepredetermined range. The pins can protrude into the cavities. It istherefore easy to handle the molds and take the molding off them.

Each of the molds may include inner rollers supported on both sides of afront portion thereof and outer rollers supported on both sides of arear portion thereof. The apparatus may further include inner and outerguide rails for guiding the inner and outer rollers, respectively, tokeep the molds horizontal and move the molds forward and gradually down.The apparatus may also include a rail and a holding roller for stoppingthe movable plate from moving down. One of the rail and the roller issupported by the lower side of the movable plate or along and below theguide rails. The other of the rail and the roller is supported along andbelow the guide rails or by the lower side of the movable plate.

While each of the molds is moved forward with its movable plate stoppedfrom moving down by the cooperation of the holding roller and the rail,the formwork and the intermediate plate move down at the same time alongthe guide rails. This protrudes the pins gradually into the cavities,taking the molding off the mold.

The apparatus may further include:

a first lift for moving up and down at the end point of the forward pathto move down each of the molds;

guide tracks extending in parallel to the forward path horizontally fromthe point where the first lift has moved the mold down, so that theguide rollers can roll on the guide tracks;

a belt conveyor extending along the guide tracks for conveying themolds; and

a second lift for lifting each of the molds from the end points of theguide tracks to the starting point of the forward path.

The mold conveyed to the end point of the forward path can be moved downby the first lift, then conveyed backward along the horizontal guidetracks by the belt conveyor, and thereafter returned securely to thestarting point of the forward path by the second lift.

The various features of novelty which characterize the invention arepointed out with particularity in the claims annexed to and forming partof the disclosure. For a better understanding of the invention, itsoperating advantages, specific objects attained by its use, referenceshould be had to the drawing and descriptive matter in which there areillustrated and described preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a schematic side view of an apparatus for manufacturing amolding continuously in accordance with a first embodiment of theinvention;

FIG. 2 is a perspective view of a honeycomb molding which can be made bythe apparatus shown in FIG. 1;

FIG. 3(a) is a sectional view taken on the line III—III of FIG. 1;

FIG. 3(b) is a sectional view taken on the line I—I of FIG. 3(a);

FIG. 4 is a sectional view taken on the line IV—IV of FIG. 1;

FIG. 5 is a schematic side view of an apparatus for manufacturing amolding continuously in accordance with a second embodiment of theinvention;

FIG. 6 is a perspective view of a honeycomb molding which can be made bythe apparatus shown in FIG. 5;

FIG. 7(a) is a sectional view taken on the line VII—VII of FIG. 5;

FIG. 7(b) is a sectional view taken on the line II—II of FIG. 7(a); and

FIG. 8 is a sectional view taken on the line VIII—VIII of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 2, a honeycomb molding A is shown. The molding A has ahoneycomb array of hexagonal tubes or spaces each defined by side wallsA2. The spaces are closed at their tops by a ceiling or top plate A1 andopen at their bottoms.

Referring now to FIG. 1, an apparatus for continuously manufacturing thehoneycomb molding A of FIG. 2 is shown. The apparatus includes an arrayof molds 1 shaped for the molding A and open at their tops. Each mold 1may be 200 mm wide between its front and rear ends and 1,000 mm long.Each mold 1 has a pair of racks 1 a formed on both sides of its bottom.Each mold 1 supports a pair of outer side rollers 1 b on both sides ofits front portion and a pair of inner side rollers 1 c on both sides ofits rear portion. The rollers 1 b and 1 c are positioned at the samelevel. The outer rollers 1 b are offset axially from the inner rollers 1c.

The molds 1 can be circulated along an endless track 2 with their opensides up by various means in the track. The track 2 consists of aforward path 2 a, a downward path 2 b, a backward path 2 c and an upwardpath 2 d. An extrusion type solid solution injector 3 is positioned inan upstream portion of the forward path 2 a. The injector 3 can extrudeand inject a solid solution as the material for a molding A into themold 1 moving under the injector. The solution is a fluid or otherwiseflowable and may be vinyl chloride resin solution or another syntheticresin solution. A pressurizer 4 is positioned immediately downstreamfrom (in front of) the injector 3. The pressurizer 4 can evenly anddownward pressurize the solid solution in each mold 1 before thesolution starts solidifying. The pressurizer 4 includes a pressureroller 4 a.

A rear booster 5 a includes a motor 7 a and a pair of gears 6 a, whichcan be driven by the motor 7 a. A front booster 5 b includes a motor 7 band a pair of gears 6 b, which can be driven by the motor 7 b. The gears6 a are spaced from the gears 6 b by a distance nearly equaling thetotal length of about four molds 1. The gears 6 a and 6 b can mesh withthe mold racks 1 a. The rear motor 7 a is greater in torque or higher inrotational speed than the front motor 7 b. The difference in output orconveying speed between the motors 7 a and 7 b can apply pressing forcewhich urges toward each other the molds 1 being driven by the boosters 5a and 5 b and the molds between them.

The forward path 2 a includes a pair of outer guide rails 8 b and a pairof inner guide rails 8 c. The rails 8 b, and 8 c extend in parallel onboth sides of the path 2 a, and can guide the side rollers 1 b and 1 c,respectively. While each mold 1 is moving along the forward path 2 a,its rollers 1 b and 1 c are kept at the same level by the rails 8 b and8 c, respectively, so that the mold is kept horizontal. The molds 1 canmove down from the forward path 2 a through the downward path 2 b to thebackward path 2 c,through which they can move backward. The backwardpath 2 c takes the form of a tunnel or trunk, and slopes slightly downto its rear. The molds 1 can be moved backward by their own weightthrough the path 2 c. It is therefore not necessary to provide a specialmeans of moving the molds 1 backward. This contributes to the saving ofpower.

A cylinder 11 is positioned on the inlet side of the forward path 2 a.The cylinder 11 can forward push the mold 1 which has moved up throughthe upward path 2 d and reached the rear end of the forward path 2 a. Acylinder 12 is positioned on the outlet side of the forward path 2 a.The cylinder 12 can backward push the mold 1 at the front end of theforward path 2 a. The cylinders 11 and 12 can push the molds 1 in theforward path 2 a in the opposite directions.

A cylinder 9 stands under the downward path 2 b, and can vertically movea table or plate 9 a, which receives the mold 1 at the front end of theforward path 2 a. Cylinder 9 can move the mold 1 on the table 9 a downto the inlet of the backward path 2 c.A cylinder 13 is positioned on theinlet side of the backward path 2 c. Cylinder 13 can push into the inletof the backward path 2 c the mold 1 moved down through the downward path2 b by the cylinder 9.

A cylinder 10 stands under the upward path 2 d, and can vertically movea table or plate 10 a, which receives the mold 1 at the outlet of thebackward path 2 c. Cylinder 10 can move the mold 1 on the table 10 a upto the rear end of the forward path 2 a.

As shown in FIGS. 3 and 4, each mold 1 includes an array of hexagonalblocks 1-1 a, a front row and a rear row of semi-hexagonal blocks 1-1 b,and a pair of side blocks 1-1 c which support the side rollers 1 b and 1c. The mold 1 also includes an intermediate plate 1-2 and a bottom plate1-3. The blocks 1-1 a, 1-1 b and 1-1 c are bolted to the top of theintermediate plate 1-2, 2, and arranged at regular intervals in the formof a honeycomb. The intermediate plate 1-2 functions as a guide forreleasing or removing the molding. The bottom plate 1-3 is positionedunder the intermediate plate 1-2, and can move up and down relative toit.

Limit bolts 14 are fixed to the intermediate plate 1-2 and extendthrough the bottom plate 1-3. Each bolt 14 has a head 14 a for limitingthe range within which the space W between the plates 1-2 and 1-3 can bechanged. Each bolt 14 is surrounded by a compression coil spring 15,which is interposed between the plates 1-2 and 1-3 to urge them awayfrom each other. The intermediate plate 1-2 has pin holes 17 formedthrough it. Each hole 17 is aligned with the space formed among adjacentthree of the blocks 1-1 a, 1-1 b and 1-1 c. Pins 16 each have a headembedded in the bottom plate 1-3, and each extend through one of theholes 17.

Normally, as shown in FIGS. 3(a) and 4, the tops of the pins 16 areflush with the top of the intermediate plate 1-2. When the intermediateplate 1-2 moves down toward the bottom plate 1-3, the top of each pin 16protrudes from the associated hole 17 into the space among theassociated three of the mold blocks 1-1 a, 1-1 b,and 1-1 c. Theprotruding pins 16 hold side walls A2 of the molding A while the blocks1-1 a, 1-1 b and 1-1 c and the intermediate plate 1-2 are moving down.This does not damage the molding A even if the pins 16 push it withgreat force, because its side walls A2 are strong.

When each mold 1 has moved to a position near the front end of theforward path 2 a and is positioned quite low, the lower side of itsbottom plate 1-3 comes into contact with holding rollers 18. Furtherdownward movement of the mold 1 protrudes the tops of the pins 16 fromthe intermediate plate 1-2, taking out the molding A. The rollers 18 aresupported at the top of the backward path 2 c, but might be supported inanother place.

In operation, the molds 1 circulate along the track 2. The injector 3injects a solid solution into the mold 1 moving under it. Subsequently,the pressure roller 4 a evenly pressurizes the solution which has notstarted solidifying yet in the mold 1. The pressure of this roller 4 ais such that the honeycomb moldings formed in the molds 1 are connectedby a ceiling A1 in the form of a belt which is as thin as possible. Thepressurizer 4 includes an adjusting wheel for arbitrarily adjusting thethickness of the ceiling A1.

The boosters 5 a and 5 b urge the mold 1 in engagement with the gears 6a and the mold 1 in engagement with the gears 6 b toward each other.This brings these two molds 1 and the molds between them into closecontact, preventing the synthetic resin solution from being leakedbetween the molds by the injection pressure.

The pressurized solution in each mold 1 is cooled and solidifies to formpart of a molding A. The mold 1 is removed from the molding A. The guiderails 8 b and 8 c keep the mold 1 horizontal. The rails 8 b and 8 climit the vertical movement of the blocks 1-1 a, 1-1 b and 1-1 c and theintermediate plate 1-2 of the mold 1 Therefore, when the mold 1 movesdown, the holding rollers 18 hold its bottom plate 1-3 against the forceof the springs 15. This narrows the space W between the plates 1-1 and1-3.

The mold 1 can be removed down from the molding A by:

the bottom plate 1-3 being able to move up and down relative to theintermediate plate 1-2;

the springs 15 operating between the intermediate plate 1-2 and thebottom plate 1-3 when the bottom plate moves up and down;

the pins 16 protruding and retracting when the bottom plate 1-3 moves upand down; and

the holding rollers 18 coming into contact with the bottom plate 1-3near the end of the removing step.

The front ends of the guide rails 8 b and 8 c are positioned immediatelybackward from the point where the removing step ends. Where the ends ofthe rails 8 b and 8 c are positioned, the bottom plate 1-3 of the mold 1disengages from the front holding rollers 18. When the mold 1 approachesthe end of the removing step, a signal is generated. In accordance withthe signal, the cylinder 9 moves the table 9 a up. Then, the mold 1 istransferred securely onto the table 9 a, and moved with it down to thelevel of the inlet of the backward path 2 c. Thereafter, the cylinder 13forces the mold 1 into the inlet of this path 2 c. Then, the mold 1 ismoved backward by its weight through the backward path 2 c. When themold 1 reaches the bottom of the upward path 2 d, it is receivedsecurely by the table 10 a. The mold 1 on the table 10 a is lifted tothe level of the inlet of the forward path 2 a by the cylinder 10.

As stated above, the cylinder 11 can forward urge the mold 1 at the rearend of the forward path 2 a, while the cylinder 12 can backward urge themold 1 at the front end of this path 2 a. While these two molds 1 andthe molds between them are moving along the path 2 a, the cylinders 11and 12 bring all these molds into close contact. This can keep theapparatus operating without preventing the smooth movement of the molds1 entering and leaving the forward path 2 a.

The material for the molding A may contain vinyl chloride, polyethyleneor another high molecular compound, and be made into solid solution at atemperature between 120 and 70 degrees C.

Referring now to FIG. 6, a honeycomb molding A′ is shown. The molding A′differs from the molding A in that the walls A2 of its hexagonal spaceseach have a U-shaped top recess A3. The recesses A3 of the walls A2 donot prevent the lawn roots in a lawn parking lot from extendinghorizontally.

Referring now to FIGS. 5, 7 a, 7 b and 8, these figures show anapparatus for continuously manufacturing the honeycomb molding A′ ofFIG. 6. The main differences between the this embodiment and the priorembodiment of the invention are discussed below. Otherwise, theembodiments are common in structure and their operations are basicallycommon.

The molds 1′ of this apparatus are shaped to form the recesses A3 in themolding A′. Each mold 1′ has two pairs of bottom rollers 18′ supportedby the lower side of its bottom plate 1-3. Each pair of rollers 18′ isspaced laterally from the other. Two horizontal rails 19 extend inparallel below the guide rails 8 a and 8 b, and are fixed to frames 20.Each pair of rollers 18′ can roll on one of the horizontal rails 19. Therollers 18′ are positioned midway between the front and rear ends of themold 1′ so that the mold can move down smoothly in the downward path 2 bof the endless track 2 without sliding on adjacent parts when therollers 18′ disengage from the horizontal rails 19. The bottom plate 1-3is not urged by springs away from the intermediate plate 1-2.

The backward path 2 c of the track 2 includes horizontal guide rails 21extending in parallel. The side rollers 1 b and 1 c of the molds 1′ canroll on these rails 21. A belt conveyor 22 extends below and along therails 21, and includes a belt 22 a. The upper portion of the belt 22 acan engage with the lateral middle of the lower side of the bottom plate1-3 of each mold 1′. The belt 22 a conveys the mold 1′ to the bottom ofthe upward path 2 d of the track 2.

Each mold 1′ has a pair of bearing rollers 23 supported on both sides ofits bottom plate 1-3. As shown in FIG. 5, two inclined guides 24 arefixed at the bottom of the downward path 2 b and near the inlet of thebackward path 2 c. Each guide 24 has a slope for guiding one of thebearing rollers 23 along it. The guide slopes can force the bottom plate1-3 down from the intermediate plate 1-2 in order to space them fromeach other. This enables the belt conveyor 22 to convey the mold 1′securely. Two other inclined guides 25 are fixed at the top of theupward path 2 d and near the inlet of the forward path 2 a. When eachmold 1′ is lifted by the cylinder 10, its bottom plate 1-3 is movedtoward the intermediate plate 1-2. When the lifted mold 1′ is movedforward, the guides 25 guide its bearing rollers 23 to space the bottomplate 1-3 down from the intermediate plate 1-2.

Referring now to FIG. 5, during operation the injector 3 injects asynthetic resin solution into the mold 1′ moving under it. The pressureroller 4 a of the pressurizer 4 subsequently evenly pressurizes thesolution which has not started solidifying yet in the mold 1′. Thehoneycomb moldings formed in the molds 1′ are connected by a ceiling A1in the form of a belt to form a continuous molding A′.

The boosters 5 a and 5 b urge the mold 1 in engagement with the gears 6a and the mold 1 in engagement with the gears 6 b toward each other.This brings these two molds 1 and the molds between them into closecontact, preventing the synthetic resin solution from being leakedbetween the molds by the injection pressure. While each mold 1′ is thusconveyed forward (to the left in FIG. 5), the solution in it issolidified by cooling. Subsequently, the mold 1′ is removed from themolding A′.

As stated above, the horizontal rails 19 extend forward from a pointnear the middle of the length of the forward path 2 a.While the mold 1′is conveyed along the sloping portions of the guide rails 8 b and 8 c,its bottom rollers 18′ come into contact with the horizontal rails 19 sothat its bottom plate 1-3 stops moving down. In the meantime, the moldblocks 1-1 a, 1-1 b and 1-1 c and the intermediate plate 1-2 of the mold1′ keep moving down. This moves the intermediate plate 1-2 toward thebottom plate 1-3 to protrude the pins 16 from the intermediate plate.The protruding pins 16 push side walls A2 of the molding A′ upward totake the molding off the mold 1′. In other words, while the molding A′is moving forward and horizontally without changing its verticalposition, the mold 1′ is removed down from the molding.

After the bottom rollers 18′ of the mold 1′ leave the horizontal rails19, the mold moves down along the downward path 2 b. While the mold 1′is moving down, it is kept substantially horizontal by the rollers 18′.After the side rollers 1 b and 1 c of the mold 1′ reach the horizontalguide rails 21, its bearing rollers 23 are guided by the inclined guides24. This spaces the bottom plate 1-3 of the mold 1′ down from theintermediate plate 1-2 to bring the bottom plate into engagement withthe conveyor belt 22 a. The belt conveyor 22 conveys the mold 1′ alongthe backward path 2 c.

After the mold 1′ reaches the upward path 2 d, it is lifted along thispath by the cylinder 10 and returns to the starting point of the forwardpath 2 a. When the mold 1′ is pushed into the forward path 2 a by thecylinder 11, the inclined guides 25 guide the bearing rollers 23 toforce the bottom plate 1-3 downward from the intermediate plate 1-2.This returns the mold 1′ to its original condition. The foregoingoperation is repeated with the molds 1′ circulated along the track 2 toform a continuous molding A′.

The mold blocks 1-1 a, 1-1 b and 1-1 c of each mold 1 or 1′might beintegral with the intermediate plate 1-2 of the mold.

While specific embodiments of the invention have been shown anddescribed in detail to illustrate the inventive principles, it will beunderstood that the invention may be embodied otherwise withoutdeparting from such principles.

What is claimed is:
 1. An apparatus for manufacturing a continuousmolding continuously by injecting a solid solution in order ofprecedence into a plurality of molds circulating in a line along anendless track, and by solidifying the injected solution, the molds eachincluding a plurality of pins which can protrude up into cavities in themold, the continuous molding consisting of a number of moldingsconnected end to end by a molded top plate, the moldings being open attheir bottoms, the apparatus comprising: conveying means forhorizontally conveying the molds in contact with each other and inseries along the track; injecting means for injecting the solution intoeach of the molds moving forward along the track, the injecting meansbeing positioned above the starting point where the conveying meansstarts conveying the molds; a pressurizer for pressing the upper surfaceof the injected solution with a predetermined pressure to make thesurface continuously flat, the pressurizer being positioned adjacentlyto and downstream from the injecting means; guide means for guiding themolds down by using the conveying force; removing means for protrudingthe pins up as the molds are moving down; and circulating means forcirculating to the starting point the molds removed from the molding. 2.An apparatus according to claim 1, wherein each of the molds includesrollers which can be guided by the guide means in such a manner that,while the mold is moving forward along the guide means and graduallydown out of close contact with the molding, the mold is kept horizontal.3. An apparatus according to claim 1, further comprising means forurging forward and backward into contact with each other at least two ofthe molds moving during a period of a molding step in which the moldsmove forward while the solution is injected into the molds.
 4. Anapparatus according to claim 1, further comprising means for urgingforward the rear end of the mold having circulated and returned to thestarting point, and for urging backward the front end of the mold at theend of the forward mold movement.
 5. An apparatus according to claim 1,wherein each of the molds includes: a formwork having the cavitiescorresponding to the molding; an intermediate plate closing the lowerside of the formwork and having pin holes, each of the pins extendingthrough one of the holes in such a manner that the pins can protrudefrom the holes into the cavities; and a movable plate in which the pinsare embedded in such a manner that the pins extend toward theintermediate plate, the movable plate being able to move toward and awayfrom the intermediate plate within a predetermined range.
 6. Anapparatus according to claim 2, further comprising means for urgingforward and backward into contact with each other at least two of themolds moving during a period of a molding step in which the molds moveforward while the solution is injected into the molds.
 7. An apparatusaccording to claim 2, further comprising means for urging forward therear end of the mold having circulated and returned to the startingpoint, and for urging backward the front end of the mold at the end ofthe forward mold movement.
 8. An apparatus according to claim 2, whereineach of the molds includes inner rollers supported on both sides of afront portion thereof and outer rollers supported on both sides of arear portion thereof, the apparatus further comprising: inner and outerguide rails for guiding the inner and outer rollers, respectively, tokeep the molds horizontal and move the molds forward and down; and arail and a holding roller for stopping the movable plate from a movingdown, one of the rail and the holding roller being supported by thelower side of the movable plate or along and below the guide rails, andthe other being supported along and below the guide rails or by thelower side of the movable plate.
 9. An apparatus according to claim 2,and further comprising: a first lift for moving up and down at the endpoint of the forward path to move down each of the molds, guide tracksextending in parallel to the forward path horizontally from the pointwhere the first lift has moved the mold down, so that the guide rollerscan roll on the guide tracks; a belt conveyor extending along the guidetracks for conveying the molds; and a second lift for lifting each ofthe molds from the end points of the guide tracks to the starting pointof the forward path.
 10. An apparatus according to claim 5, wherein eachof the molds includes inner rollers supported on both sides of a frontportion thereof and outer rollers supported on both sides of a rearportion thereof, the apparatus further comprising: inner and outer guiderails for guiding the inner and outer rollers, respectively, to keep themolds horizontal and move the molds forward and down; and a rail and aholding roller for stopping the movable plate from a moving down, one ofthe rail and the holding roller being supported by the lower side of themovable plate or along and below the guide rails, and the other beingsupported along and below the guide rails or by the lower side of themovable plate.
 11. An apparatus according to claim 8, and furthercomprising: a first lift for moving up and down at the end point of theforward path to move down each of the molds, guide tracks extending inparallel to the forward path horizontally from the point where the firstlift has moved the mold down, so that the guide rollers can roll on theguide tracks; a belt conveyor extending along the guide tracks forconveying the molds; and a second lift for lifting each of the moldsfrom the end points of the guide tracks to the starting point of theforward path.
 12. An apparatus according to claim 10, and furthercomprising: a first lift for moving up and down at the end point of theforward path to move down each of the molds, guide tracks extending inparallel to the forward path horizontally from the point where the firstlift has moved the mold down, so that the guide rollers can roll on theguide tracks; a belt conveyor extending along the guide tracks forconveying the molds; and a second lift for lifting each of the moldsfrom the end points of the guide tracks to the starting point of theforward path.